Player movement script like in FPS

I have 2 scripts, which make player move like in the FPS game. But it don't move to that direction, to which player are looking - it always move to the same direction, regardless of the direction of the camera..

mouselook.cs

 float yRotation;
 float xRotation;
 float lookSensitivity = 5;
 float currentXRotation;
 float currentYRotation;
 float yRotationV;
 float xRotationV;
 float lookSmoothnes = 0.1f; 
 
 void Update ()
 {
     yRotation += Input.GetAxis("Mouse X") * lookSensitivity;
     xRotation -= Input.GetAxis("Mouse Y") * lookSensitivity;
     xRotation = Mathf.Clamp(xRotation, -80, 100);
     currentXRotation = Mathf.SmoothDamp(currentXRotation, xRotation, ref xRotationV, lookSmoothnes);
     currentYRotation = Mathf.SmoothDamp(currentYRotation, yRotation, ref yRotationV, lookSmoothnes);
     transform.rotation = Quaternion.Euler(xRotation, yRotation, 0);
 }

playermovement.cs

 public float walkSpeed = 6.0F;
 public float jumpSpeed = 8.0F;
 public float runSpeed = 8.0F;
 public float gravity = 20.0F;
 
 private Vector3 moveDirection = Vector3.zero;
 private CharacterController controller;
 
 void Start()
 {
     controller = GetComponent<CharacterController>();
 }
 
 void Update()
 {
     if (controller.isGrounded)
     {
         moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
         moveDirection = transform.TransformDirection(moveDirection);
         moveDirection *= walkSpeed;
         if (Input.GetButton("Jump"))
             moveDirection.y = jumpSpeed;
     }
     moveDirection.y -= gravity * Time.deltaTime;
     controller.Move(moveDirection * Time.deltaTime);
 }